IPTG

IPTG

IPTG (Isopropyl β-D-1-thiogalactopyranoside) is a widely used molecular biology reagent that serves as an inducer for gene expression in systems utilizing the lac operon. Its ability to mimic allolactose, a natural lactose metabolite, allows it to activate transcription of genes under the control of the lac operator, making it an essential tool in recombinant protein production.

Chemical Properties

• CAS Number: 367-93-1
• MDL No.: MFCD00063273
• Catalog Number: A823371
• EINECS: Not available
• Molecular Formula: C₉H₁₈O₅S
• Molecular Weight: 238.30 g/mol
• Boiling Point: 438.4 °C at 760 mmHg
• Melting Point: 105 °C
• Flash Point: 218.9 ± 28.7 °C
• Density: Not specified (typically around 1.3329 g/cm³)
• Appearance: White or white crystalline powder
• Storage Conditions: Store at 2–8 °C for long-term stability (months).
• Optical Rotation: -31° (c=1, water)
• Refractivity: 1.5060 (estimate)

Mechanism of Action

IPTG functions as a non-hydrolyzable analog of allolactose, binding to the lac repressor protein and preventing it from attaching to the lac operator region. This action releases the repression on downstream genes, allowing for transcription and subsequent translation of proteins such as β-galactosidase. Unlike allolactose, IPTG is not metabolized by E. coli, maintaining a consistent concentration during experiments.

Applications

1. Gene Expression Induction:
   • IPTG is primarily used to induce protein expression in recombinant DNA systems, particularly in E. coli strains that utilize the lac operon for controlled gene expression.
2. Protein Purification:
   • It facilitates the overexpression of target proteins, which can be purified using affinity chromatography techniques, often in conjunction with tags such as His-tags.
3. Blue/White Screening:
   • IPTG is commonly used in cloning experiments alongside X-Gal to visually distinguish between recombinant and non-recombinant bacterial colonies based on color change.
4. Biochemical Research:
   • It is employed in various studies involving enzyme kinetics and metabolic pathways, aiding in understanding cellular processes and gene regulation.
5. Synthetic Biology:
   • IPTG is utilized in synthetic biology applications where precise control over gene expression is required for engineered biological systems.

Safety Profile

While IPTG is generally considered safe for laboratory use, standard safety protocols should be followed when handling this compound. Appropriate personal protective equipment (PPE) should be worn to minimize exposure.

Conclusion

IPTG (CAS No. 367-93-1) is a critical reagent in molecular biology, facilitating gene expression and protein production through its role as an inducer of the lac operon. Its unique properties make it indispensable for researchers working with recombinant proteins and genetic engineering.

Citations:

1. https://www.gbiosciences.com/Buffers-Reagents-Chemicals/Molecular-Biology-Related-Buffers-Chemicals/IPTG-Isopropyl-D-1-thiogalactopyranoside
2. https://www.chemicalbook.com/article/isopropyl-d-1-thiogalactopyranoside-iptg-a-compound-for-scientific-research.htm
3. https://www.chemicalbook.com/ChemicalProductProperty_EN_CB2121723.htm
4. https://agscientific.com/blog/iptg-facts-protocols.html
5. https://en.wikipedia.org/wiki/Isopropyl_%CE%B2-D-1-thiogalactopyranoside
6. https://www.bioline.com/iptg.html
7. https://www.glentham.com/en/products/product/GC6586/
8. https://www.nzytech.com/en/mb026-iptg/